aboutsummaryrefslogtreecommitdiff
path: root/sys/dev/tl/if_tlreg.h
blob: 51fb6820bd8e8ce2a8d9fe879e87aad87f749261 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1997, 1998
 *	Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD$
 */

struct tl_type {
	u_int16_t		tl_vid;
	u_int16_t		tl_did;
	const char		*tl_name;
};

/*
 * ThunderLAN TX/RX list format. The TX and RX lists are pretty much
 * identical: the list begins with a 32-bit forward pointer which points
 * at the next list in the chain, followed by 16 bits for the total
 * frame size, and a 16 bit status field. This is followed by a series
 * of 10 32-bit data count/data address pairs that point to the fragments
 * that make up the complete frame.
 */

#define TL_MAXFRAGS		10
#define TL_RX_LIST_CNT		64
#define TL_TX_LIST_CNT		128
#define TL_MIN_FRAMELEN		64

struct tl_frag {
	u_int32_t		tlist_dcnt;
	u_int32_t		tlist_dadr;
};

struct tl_list {
	u_int32_t		tlist_fptr;	/* phys address of next list */
	u_int16_t		tlist_cstat;	/* status word */
	u_int16_t		tlist_frsize;	/* size of data in frame */
	struct tl_frag		tl_frag[TL_MAXFRAGS];
};

/*
 * This is a special case of an RX list. By setting the One_Frag
 * bit in the NETCONFIG register, the driver can force the ThunderLAN
 * chip to use only one fragment when DMAing RX frames.
 */

struct tl_list_onefrag {
	u_int32_t		tlist_fptr;
	u_int16_t		tlist_cstat;
	u_int16_t		tlist_frsize;
	struct tl_frag		tl_frag;
};

struct tl_list_data {
	struct tl_list_onefrag	tl_rx_list[TL_RX_LIST_CNT];
	struct tl_list		tl_tx_list[TL_TX_LIST_CNT];
	unsigned char		tl_pad[TL_MIN_FRAMELEN];
};

struct tl_chain {
	struct tl_list		*tl_ptr;
	struct mbuf		*tl_mbuf;
	struct tl_chain		*tl_next;
};

struct tl_chain_onefrag {
	struct tl_list_onefrag	*tl_ptr;
	struct mbuf		*tl_mbuf;
	struct tl_chain_onefrag	*tl_next;
};

struct tl_chain_data {
	struct tl_chain_onefrag	tl_rx_chain[TL_RX_LIST_CNT];
	struct tl_chain		tl_tx_chain[TL_TX_LIST_CNT];

	struct tl_chain_onefrag	*tl_rx_head;
	struct tl_chain_onefrag	*tl_rx_tail;

	struct tl_chain		*tl_tx_head;
	struct tl_chain		*tl_tx_tail;
	struct tl_chain		*tl_tx_free;
};

struct tl_softc {
	struct ifnet		*tl_ifp;
	device_t		tl_dev;
	struct ifmedia		ifmedia;	/* media info */
	void			*tl_intrhand;
	struct resource		*tl_irq;
	struct resource		*tl_res;
	device_t		tl_miibus;
	u_int8_t		tl_eeaddr;
	struct tl_list_data	*tl_ldata;	/* TX/RX lists and mbufs */
	struct tl_chain_data	tl_cdata;
	u_int8_t		tl_txeoc;
	u_int8_t		tl_bitrate;
	int			tl_if_flags;
	struct callout		tl_stat_callout;
	struct mtx		tl_mtx;
	int			tl_timer;
};

#define	TL_LOCK(_sc)		mtx_lock(&(_sc)->tl_mtx)
#define	TL_UNLOCK(_sc)		mtx_unlock(&(_sc)->tl_mtx)
#define	TL_LOCK_ASSERT(_sc)	mtx_assert(&(_sc)->tl_mtx, MA_OWNED)

/*
 * Transmit interrupt threshold.
 */
#define TX_THR		0x00000004

/*
 * General constants that are fun to know.
 *
 * The ThunderLAN controller is made by Texas Instruments. The
 * manual indicates that if the EEPROM checksum fails, the PCI
 * vendor and device ID registers will be loaded with TI-specific
 * values.
 */
#define	TI_VENDORID		0x104C
#define	TI_DEVICEID_THUNDERLAN	0x0500

/*
 * These are the PCI vendor and device IDs for Compaq ethernet
 * adapters based on the ThunderLAN controller.
 */
#define COMPAQ_VENDORID				0x0E11
#define COMPAQ_DEVICEID_NETEL_10_100		0xAE32
#define COMPAQ_DEVICEID_NETEL_UNKNOWN		0xAE33
#define COMPAQ_DEVICEID_NETEL_10		0xAE34
#define COMPAQ_DEVICEID_NETFLEX_3P_INTEGRATED	0xAE35
#define COMPAQ_DEVICEID_NETEL_10_100_DUAL	0xAE40
#define COMPAQ_DEVICEID_NETEL_10_100_PROLIANT	0xAE43
#define COMPAQ_DEVICEID_NETEL_10_100_EMBEDDED	0xB011
#define COMPAQ_DEVICEID_NETEL_10_T2_UTP_COAX	0xB012
#define COMPAQ_DEVICEID_NETEL_10_100_TX_UTP	0xB030
#define COMPAQ_DEVICEID_NETFLEX_3P		0xF130
#define COMPAQ_DEVICEID_NETFLEX_3P_BNC		0xF150

/*
 * These are the PCI vendor and device IDs for Olicom
 * adapters based on the ThunderLAN controller.
 */
#define OLICOM_VENDORID				0x108D
#define OLICOM_DEVICEID_OC2183			0x0013
#define OLICOM_DEVICEID_OC2325			0x0012
#define OLICOM_DEVICEID_OC2326			0x0014

/*
 * PCI low memory base and low I/O base
 */
#define TL_PCI_LOIO		0x10
#define TL_PCI_LOMEM		0x14

/*
 * PCI latency timer (it's actually 0x0D, but we want a value
 * that's longword aligned).
 */
#define TL_PCI_LATENCY_TIMER	0x0C

#define	TL_DIO_ADDR_INC		0x8000	/* Increment addr on each read */
#define TL_DIO_RAM_SEL		0x4000	/* RAM address select */
#define	TL_DIO_ADDR_MASK	0x3FFF	/* address bits mask */

/*
 * Interrupt types
 */
#define TL_INTR_INVALID		0x0
#define TL_INTR_TXEOF		0x1
#define TL_INTR_STATOFLOW	0x2
#define TL_INTR_RXEOF		0x3
#define TL_INTR_DUMMY		0x4
#define TL_INTR_TXEOC		0x5
#define TL_INTR_ADCHK		0x6
#define TL_INTR_RXEOC		0x7

#define TL_INT_MASK		0x001C
#define TL_VEC_MASK		0x1FE0

/*
 * Host command register bits
 */
#define TL_CMD_GO               0x80000000
#define TL_CMD_STOP             0x40000000
#define TL_CMD_ACK              0x20000000
#define TL_CMD_CHSEL7		0x10000000
#define TL_CMD_CHSEL6		0x08000000
#define TL_CMD_CHSEL5		0x04000000
#define TL_CMD_CHSEL4		0x02000000
#define TL_CMD_CHSEL3		0x01000000
#define TL_CMD_CHSEL2           0x00800000
#define TL_CMD_CHSEL1           0x00400000
#define TL_CMD_CHSEL0           0x00200000
#define TL_CMD_EOC              0x00100000
#define TL_CMD_RT               0x00080000
#define TL_CMD_NES              0x00040000
#define TL_CMD_ZERO0            0x00020000
#define TL_CMD_ZERO1            0x00010000
#define TL_CMD_ADRST            0x00008000
#define TL_CMD_LDTMR            0x00004000
#define TL_CMD_LDTHR            0x00002000
#define TL_CMD_REQINT           0x00001000
#define TL_CMD_INTSOFF          0x00000800
#define TL_CMD_INTSON		0x00000400
#define TL_CMD_RSVD0		0x00000200
#define TL_CMD_RSVD1		0x00000100
#define TL_CMD_ACK7		0x00000080
#define TL_CMD_ACK6		0x00000040
#define TL_CMD_ACK5		0x00000020
#define TL_CMD_ACK4		0x00000010
#define TL_CMD_ACK3		0x00000008
#define TL_CMD_ACK2		0x00000004
#define TL_CMD_ACK1		0x00000002
#define TL_CMD_ACK0		0x00000001

#define TL_CMD_CHSEL_MASK	0x01FE0000
#define TL_CMD_ACK_MASK		0xFF

/*
 * EEPROM address where station address resides.
 */
#define TL_EEPROM_EADDR		0x83
#define TL_EEPROM_EADDR2	0x99
#define TL_EEPROM_EADDR3	0xAF
#define TL_EEPROM_EADDR_OC	0xF8	/* Olicom cards use a different
					   address than Compaqs. */
/*
 * ThunderLAN host command register offsets.
 * (Can be accessed either by IO ports or memory map.)
 */
#define TL_HOSTCMD		0x00
#define TL_CH_PARM		0x04
#define TL_DIO_ADDR		0x08
#define TL_HOST_INT		0x0A
#define TL_DIO_DATA		0x0C

/*
 * ThunderLAN internal registers
 */
#define TL_NETCMD		0x00
#define TL_NETSIO		0x01
#define TL_NETSTS		0x02
#define TL_NETMASK		0x03

#define TL_NETCONFIG		0x04
#define TL_MANTEST		0x06

#define TL_VENID_LSB		0x08
#define TL_VENID_MSB		0x09
#define TL_DEVID_LSB		0x0A
#define TL_DEVID_MSB		0x0B

#define TL_REVISION		0x0C
#define TL_SUBCLASS		0x0D
#define TL_MINLAT		0x0E
#define TL_MAXLAT		0x0F

#define TL_AREG0_B5		0x10
#define TL_AREG0_B4		0x11
#define TL_AREG0_B3		0x12
#define TL_AREG0_B2		0x13

#define TL_AREG0_B1		0x14
#define TL_AREG0_B0		0x15
#define TL_AREG1_B5		0x16
#define TL_AREG1_B4		0x17

#define TL_AREG1_B3		0x18
#define TL_AREG1_B2		0x19
#define TL_AREG1_B1		0x1A
#define TL_AREG1_B0		0x1B

#define TL_AREG2_B5		0x1C
#define TL_AREG2_B4		0x1D
#define TL_AREG2_B3		0x1E
#define TL_AREG2_B2		0x1F

#define TL_AREG2_B1		0x20
#define TL_AREG2_B0		0x21
#define TL_AREG3_B5		0x22
#define TL_AREG3_B4		0x23

#define TL_AREG3_B3		0x24
#define TL_AREG3_B2		0x25
#define TL_AREG3_B1		0x26
#define TL_AREG3_B0		0x27

#define TL_HASH1		0x28
#define TL_HASH2		0x2C
#define TL_TXGOODFRAMES		0x30
#define TL_TXUNDERRUN		0x33
#define TL_RXGOODFRAMES		0x34
#define TL_RXOVERRUN		0x37
#define TL_DEFEREDTX		0x38
#define TL_CRCERROR		0x3A
#define TL_CODEERROR		0x3B
#define TL_MULTICOLTX		0x3C
#define TL_SINGLECOLTX		0x3E
#define TL_EXCESSIVECOL		0x40
#define TL_LATECOL		0x41
#define TL_CARRIERLOSS		0x42
#define TL_ACOMMIT		0x43
#define TL_LDREG		0x44
#define TL_BSIZEREG		0x45
#define TL_MAXRX		0x46

/*
 * ThunderLAN SIO register bits
 */
#define TL_SIO_MINTEN		0x80
#define TL_SIO_ECLOK		0x40
#define TL_SIO_ETXEN		0x20
#define TL_SIO_EDATA		0x10
#define TL_SIO_NMRST		0x08
#define TL_SIO_MCLK		0x04
#define TL_SIO_MTXEN		0x02
#define TL_SIO_MDATA		0x01

/*
 * Thunderlan NETCONFIG bits
 */
#define TL_CFG_RCLKTEST		0x8000
#define TL_CFG_TCLKTEST		0x4000
#define TL_CFG_BITRATE		0x2000
#define TL_CFG_RXCRC		0x1000
#define TL_CFG_PEF		0x0800
#define TL_CFG_ONEFRAG		0x0400
#define TL_CFG_ONECHAN		0x0200
#define TL_CFG_MTEST		0x0100
#define TL_CFG_PHYEN		0x0080
#define TL_CFG_MACSEL6		0x0040
#define TL_CFG_MACSEL5		0x0020
#define TL_CFG_MACSEL4		0x0010
#define TL_CFG_MACSEL3		0x0008
#define TL_CFG_MACSEL2		0x0004
#define TL_CFG_MACSEL1		0x0002
#define TL_CFG_MACSEL0		0x0001

/*
 * ThunderLAN NETSTS bits
 */
#define TL_STS_MIRQ		0x80
#define TL_STS_HBEAT		0x40
#define TL_STS_TXSTOP		0x20
#define TL_STS_RXSTOP		0x10

/*
 * ThunderLAN NETCMD bits
 */
#define TL_CMD_NRESET		0x80
#define TL_CMD_NWRAP		0x40
#define TL_CMD_CSF		0x20
#define TL_CMD_CAF		0x10
#define TL_CMD_NOBRX		0x08
#define TL_CMD_DUPLEX		0x04
#define TL_CMD_TRFRAM		0x02
#define TL_CMD_TXPACE		0x01

/*
 * ThunderLAN NETMASK bits
 */
#define TL_MASK_MASK7		0x80
#define TL_MASK_MASK6		0x40
#define TL_MASK_MASK5		0x20
#define TL_MASK_MASK4		0x10

#define TL_LAST_FRAG		0x80000000
#define TL_CSTAT_UNUSED		0x8000
#define TL_CSTAT_FRAMECMP	0x4000
#define TL_CSTAT_READY		0x3000
#define TL_CSTAT_UNUSED13	0x2000
#define TL_CSTAT_UNUSED12	0x1000
#define TL_CSTAT_EOC		0x0800
#define TL_CSTAT_RXERROR	0x0400
#define TL_CSTAT_PASSCRC	0x0200
#define TL_CSTAT_DPRIO		0x0100

#define TL_FRAME_MASK		0x00FFFFFF
#define tl_tx_goodframes(x)	(x.tl_txstat & TL_FRAME_MASK)
#define tl_tx_underrun(x)	((x.tl_txstat & ~TL_FRAME_MASK) >> 24)
#define tl_rx_goodframes(x)	(x.tl_rxstat & TL_FRAME_MASK)
#define tl_rx_overrun(x)	((x.tl_rxstat & ~TL_FRAME_MASK) >> 24)

struct tl_stats {
	u_int32_t		tl_txstat;
	u_int32_t		tl_rxstat;
	u_int16_t		tl_deferred;
	u_int8_t		tl_crc_errors;
	u_int8_t		tl_code_errors;
	u_int16_t		tl_tx_multi_collision;
	u_int16_t		tl_tx_single_collision;
	u_int8_t		tl_excessive_collision;
	u_int8_t		tl_late_collision;
	u_int8_t		tl_carrier_loss;
	u_int8_t		acommit;
};

/*
 * ACOMMIT register bits. These are used only when a bitrate
 * PHY is selected ('bitrate' bit in netconfig register is set).
 */
#define TL_AC_MTXER		0x01	/* reserved */
#define TL_AC_MTXD1		0x02	/* 0 == 10baseT 1 == AUI */
#define TL_AC_MTXD2		0x04	/* loopback disable */
#define TL_AC_MTXD3		0x08	/* full duplex disable */

#define TL_AC_TXTHRESH		0xF0
#define TL_AC_TXTHRESH_16LONG	0x00
#define TL_AC_TXTHRESH_32LONG	0x10
#define TL_AC_TXTHRESH_64LONG	0x20
#define TL_AC_TXTHRESH_128LONG	0x30
#define TL_AC_TXTHRESH_256LONG	0x40
#define TL_AC_TXTHRESH_WHOLEPKT	0x50

/*
 * PCI burst size register (TL_BSIZEREG).
 */
#define TL_RXBURST		0x0F
#define TL_TXBURST		0xF0

#define TL_RXBURST_4LONG	0x00
#define TL_RXBURST_8LONG	0x01
#define TL_RXBURST_16LONG	0x02
#define TL_RXBURST_32LONG	0x03
#define TL_RXBURST_64LONG	0x04
#define TL_RXBURST_128LONG	0x05

#define TL_TXBURST_4LONG	0x00
#define TL_TXBURST_8LONG	0x10
#define TL_TXBURST_16LONG	0x20
#define TL_TXBURST_32LONG	0x30
#define TL_TXBURST_64LONG	0x40
#define TL_TXBURST_128LONG	0x50

/*
 * register space access macros
 */
#define CSR_WRITE_4(sc, reg, val)	bus_write_4(sc->tl_res, reg, val)
#define CSR_WRITE_2(sc, reg, val)	bus_write_2(sc->tl_res, reg, val)
#define CSR_WRITE_1(sc, reg, val)	bus_write_1(sc->tl_res, reg, val)

#define CSR_READ_4(sc, reg)		bus_read_4(sc->tl_res, reg)
#define CSR_READ_2(sc, reg)		bus_read_2(sc->tl_res, reg)
#define CSR_READ_1(sc, reg)		bus_read_1(sc->tl_res, reg)

#define	CSR_BARRIER(sc, reg, length, flags)				\
	bus_barrier(sc->tl_res, reg, length, flags)

#define CMD_PUT(sc, x) CSR_WRITE_4(sc, TL_HOSTCMD, x)
#define CMD_SET(sc, x)	\
	CSR_WRITE_4(sc, TL_HOSTCMD, CSR_READ_4(sc, TL_HOSTCMD) | (x))
#define CMD_CLR(sc, x)	\
	CSR_WRITE_4(sc, TL_HOSTCMD, CSR_READ_4(sc, TL_HOSTCMD) & ~(x))

/*
 * ThunderLAN adapters typically have a serial EEPROM containing
 * configuration information. The main reason we're interested in
 * it is because it also contains the adapters's station address.
 *
 * Access to the EEPROM is a bit goofy since it is a serial device:
 * you have to do reads and writes one bit at a time. The state of
 * the DATA bit can only change while the CLOCK line is held low.
 * Transactions work basically like this:
 *
 * 1) Send the EEPROM_START sequence to prepare the EEPROM for
 *    accepting commands. This pulls the clock high, sets
 *    the data bit to 0, enables transmission to the EEPROM,
 *    pulls the data bit up to 1, then pulls the clock low.
 *    The idea is to do a 0 to 1 transition of the data bit
 *    while the clock pin is held high.
 *
 * 2) To write a bit to the EEPROM, set the TXENABLE bit, then
 *    set the EDATA bit to send a 1 or clear it to send a 0.
 *    Finally, set and then clear ECLOK. Strobing the clock
 *    transmits the bit. After 8 bits have been written, the
 *    EEPROM should respond with an ACK, which should be read.
 *
 * 3) To read a bit from the EEPROM, clear the TXENABLE bit,
 *    then set ECLOK. The bit can then be read by reading EDATA.
 *    ECLOCK should then be cleared again. This can be repeated
 *    8 times to read a whole byte, after which the 
 *
 * 4) We need to send the address byte to the EEPROM. For this
 *    we have to send the write control byte to the EEPROM to
 *    tell it to accept data. The byte is 0xA0. The EEPROM should
 *    ack this. The address byte can be send after that.
 *
 * 5) Now we have to tell the EEPROM to send us data. For that we
 *    have to transmit the read control byte, which is 0xA1. This
 *    byte should also be acked. We can then read the data bits
 *    from the EEPROM.
 *
 * 6) When we're all finished, send the EEPROM_STOP sequence.
 *
 * Note that we use the ThunderLAN's NetSio register to access the
 * EEPROM, however there is an alternate method. There is a PCI NVRAM
 * register at PCI offset 0xB4 which can also be used with minor changes.
 * The difference is that access to PCI registers via pci_conf_read()
 * and pci_conf_write() is done using programmed I/O, which we want to
 * avoid.
 */

/*
 * Note that EEPROM_START leaves transmission enabled.
 */
#define EEPROM_START							\
	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock pin high */\
	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Set DATA bit to 1 */	\
	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Enable xmit to write bit */\
	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Pull DATA bit to 0 again */\
	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock low again */

/*
 * EEPROM_STOP ends access to the EEPROM and clears the ETXEN bit so
 * that no further data can be written to the EEPROM I/O pin.
 */
#define EEPROM_STOP							\
	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Disable xmit */	\
	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Pull DATA to 0 */	\
	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock high */	\
	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Enable xmit */	\
	tl_dio_setbit(sc, TL_NETSIO, TL_SIO_EDATA); /* Toggle DATA to 1 */	\
	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ETXEN); /* Disable xmit. */	\
	tl_dio_clrbit(sc, TL_NETSIO, TL_SIO_ECLOK); /* Pull clock low again */


/*
 * Microchip Technology 24Cxx EEPROM control bytes
 */
#define EEPROM_CTL_READ			0xA1	/* 0101 0001 */
#define EEPROM_CTL_WRITE		0xA0	/* 0101 0000 */